1. Field of the Invention
The invention relates in general to an apparatus for supporting a monitor, and more particularly to an apparatus for supporting a liquid crystal display (LCD) and rotating the LCD with respect to the base.
2. Description of the Related Art
In order for a monitor, such as a liquid crystal display (LCD), to be rotated forward and backward, the supporting apparatus of the monitor or the LCD need an angle adjustment design. Generally, the apparatus for supporting the LCD comprises a supporting arm for leading the rotation of LCD, wherein the supporting arm is fastened to the lower side of LCD.
FIG. 1A is a side view of a conventional apparatus for supporting the LCD. The conventional apparatus for supporting the LCD comprises a shaft 102, the angle control elements 104a and 104b, and the clasps 106a and 106b mounted on the shaft 102. Additionally, a pedestal 108 is provided for the apparatus for supporting the LCD. During assembly, the assembled shaft 102 is inserted through the holes of the pedestal 108 and the supporting frame 110, and then secured by the screw caps 112a and 112b. The frictional torques on the two ends of the shaft 102 are produced, due to the rotation of apparatus, and the magnitudes thereof are different. For example, one end of shaft 102 (close to the screw cap 112a) produces 45 kg/m of frictional torque, and the other end (close to the screw cap 112b) produces 25 kg/m of frictional torque. Also, the shaft 102 is a combination of sectional cores; for example, two cores are respectively situated in the right and left sides of the angle control element 104a. The supporting frame 110 embedded in a supporting arm can be rotated in a small angle range by gently applying an external force; meanwhile, the whole shaft 102 is rotated with respect to the supporting frame 110. If greater external force is applied to the supporting frame 110, the supporting frame 110 can be rotated to a larger angle; meanwhile, only one core is rotated with respect to the supporting frame 110 and the other core is sustained in the stationary state.
FIG. 1B and FIG. 1C are side views of the angle control elements in FIG. 1A. It is assumed that the LCD can be rotated in the range of 2 degrees forward and 60 degrees backward. There is a cut on the upper edge of the angle control element 104a, as shown in FIG. 1B. The cut, divided by the central line (dash line), is split into a 2-degree angle and a 20-degree angle. There is a cut on the lower edge of the angle control element 104b, as shown in FIG. 1C. The cut, divided by the central line (dash line), is split into two 60-degree angles. When the supporting frame 110 of the LCD is vertical to the base, the central lines of the angle control elements 104a and 104b are parallel to the clasps 106a and 106b, respectively. When the LCD is rotated, the shaft 102 is rotated with respect to the supporting frame 210, and the clasps 106a and 106b respectively slide along the cuts of the angle control elements 104a and 104b. When the clasps 106a and 106b hit the risen edges of the angle control elements 104a and 104b, rotation of the supporting frame 110 stopped. If the supporting frame is rotated in the range of 2 degrees forward to 20 degrees backward, the whole shaft 102 is driven. If it is desired to rotate the supporting frame 110 to 60 degrees backward, then a larger force is needed for driving the shaft core at the left side of the angle control element 104a; meanwhile, the shaft core at the right side of the angle control element 104b is sustained, and the clasp 106 keeps sliding along the edge of the cut of the angle control element 104b until hitting the risen edge thereof.
According to the description above, the conventional apparatus for supporting the LCD has a drawback of highly cost due to the combination of the two sectional cores. In addition, magnitude of the frictional torques on the two ends of the shaft 102 are different, the end of the shaft 102 producing less frictional torque being weaker than the other end and easier to be damaged. Also, manual adjustment for adjusting the produced torques is required during assembly. It is time-consuming and labor-intensive. If the diameter of the core is increased for bearing the larger external force, the size of the apparatus for supporting the LCD also increases. Additionally, a pedestal is required on which the apparatus for supporting the LCD is mounted, thereby restricting the potential for developing a lighter and smaller base of the monitor.